Track regex line for new naming convention in flavor tagging variables

The goal of this MR is to add a track regex line so as to be consistent with a new naming convention for variables used in flavor tagging, implemented in this previous MR !76058 (merged) by @dguest.

In particular, this change is needed to be able to run athena inference on ML models trained with samples that use this new naming convention (lifetimeSigned.* variables).

Tagging @svanstro, @hartman, @lcadamur, @mfujimot, @tstreble.